abnormal blood flow

examples of complications that lead to abnormal blood flow

dvt

atrial fibrilation

what is deep vein thrombosis (DVT)?

clot formation in deep veins of extremities or central vasculature

what is dvt commonly associated with?

sluggish, restricted, or stagnant blood flow

what can cause dvt?

immobility

indwelling devices → can be in large vessels (central lines)

hypercoagulable states (postoperative, pregnancy, cancer)

what are the types of DVT?

occlusive = full DVT

partially-occlusive = takes up half of vein

non-occlusive = small DVT

describes how much circulation is compromised

what is the risk if the clot dislodges?

thromboembolism

ischemia and necrosis where clot lodges

s/s of dvt

edema

erythema

warmth

pain and tenderness

definitive dx of dvt

confirm with ultrasound of affected site

• see which vessel has a clot and how occlusive it is

treatment options for dvt

anticoagulation Rx:

• heparin

• warfarin or DOACs (apixaban, rivaroxaban)

greenfield filter

thrombectomy (for fully occlusive DVT)

dvt prevention

mechanical methods

early mobilization ASAP

SCDs: stimulate calf muscles and vasculature

• discourages stasis and venous pooling of blood in LE

what are the two types of heparin?

unfractioned heparin (UFH) = heparin

low-molecular weight (LMWH) = enoxaparin (Lovenox) and dalteparin (Fragmin)

heparin vs. enoxaparin: which is more aggressive?

heparin: large molecule biologic

enoxaparin: small molecule, synthetic

heparin vs. enoxaparin: what do they do?

heparin: activates antithrombin → inactivates thrombin (IIa), Xa, IXa

enoxaparin: mainly inhibits FXa (via antithrombin)

heparin vs. enoxaparin: route

heparin: IV or SQ admin → continuous infusion

enoxaparin: SQ admin only

heparin vs. enoxaparin: which as a faster onset of action?

heparin: 0-30 min

enoxaparin: 3-5 hr

heparin vs. enoxaparin: dosage

heparin: adjustable dosage

enoxaparin: fixed dosage → once a day

heparin vs. enoxaparin: which one requires monitoring and what?

heparin: aPTT monitoring required

enoxaparin: no routine aPTT monitoring

heparin vs. enoxaparin: which one has a higher risk?

heparin

need a 2nd nurse to check dosage, patient’s labs, orders

warning for heparin and enoxaparin

do not give both → lethal bleeding risk

what is the antidote for heparin?

protamine sulfate

contraindications for anticoagulants

drug allergy

active acute bleeding or high risk for such an occurrence → recent surgery

pregnancy: avoid warfarin (use heparin/LMWH)

epidural catheters: time LMWH doses carefully (hematoma risk)

monitor for heparin-induced thrombocytopenia (HIT)

alternatives for anticoagulants

IVC filter (aka “Greenfield” filter)

• temporary

• may stop the clot from getting to the lungs → the filter will catch the clot

thrombectomy

what is atrial fibrillation (afib)?

absence of coordinated, rhythmic atrial contractions

• most common arrhythmia in the clinical setting

• risk rises with age

• caused by a variety of stressors

what does the quivering atria allow for?

stasis of blood and subsequent clot formation

a left atrial clot leads to what?

L ventricle → aorta → brain → STROKE

a right atrial clot leads to what?

R ventricle → lungs → PE

treatment options for atrial fibrillation

identify and treat underlying cause (many causes → takes time)

nonsurgical procedures

• cardioversion

• ablation

surgical procedures:

• MAZE

• pacemaker

Rx:

• antiarrhythmics

• anticoagulants

what is warfarin (Coumadin)?

vitamin K antagonist (↓ factors II, VII, IX, X)

• synthetic coumarin derivative

metabolized in the liver and renally excreted

warfarin route and onset of action

oral admin only

onset of action: 24-72 hr

may require heparin “bridge” tx

warfarin dosage

adjusted to achieve therapeutic PT/INR levels

what monitoring is required when a patient is on warfarin?

PT/INR monitoring required

• daily for 5 days

• twice a week x2 weeks

• once a week x2 months

• every 2-4 weeks after that

• therapeutic INR range 2-3

warfarin has a high risk of what?

high risk for vitamin K → coagulation cascade is thrown off

what is the antidote for warfarin?

vitamin K is given PO or IV (phytonadione, Aquamephyton)

• more vitamin K basically

nursing considerations for warfarin

monitor for therapeutic effect

avoid NSAIDs

institute bleeding precautions

antidote is vitamin K